12.5-12.8

12.5-12.8 - Predicting Acid Strengths - Summary For H-F,...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Predicting Acid Strengths - Summary For H-F, H-Cl, H-Br, and H-I: the strongest acid has the weakest bond H-I > H-Br > H-Cl > H-F Section 12.5 For H-F, H-OH, H-NH 2 , and H-CH 3 : the strongest acid has the most polar bond H-F > H-OH > H-NH 2 > H-CH 3 For Oxoacids with a differing number of oxygens: the strongest acid has the highest oxidation state (or most oxygen) HNO 3 > HNO 2 For Oxoacids with a different central atom : the strongest acid has the most electronegative central atom HClO 4 > HBrO 4 > HIO 4 Section 12.5 Predicting Base Strengths In general, the factors that make a strong acid produce a weak conjugate base Bases with a different central atom: Base strength depends on Electronegativity of central atom ClO 1- < BrO 1- More electronegative, more e- withdrawing Less electronegative, less e- withdrawing Weaker base Stronger base O Cl O Br - - Strong Acid = Weak Conjugate Base Weak Acid = Strong Conjugate Base stronger acid weaker acid O Cll H O Br H Section 12.5 Predicting Acid and Base Strengths weaker conj.base stronger conj. base O Br - O - Methyl groups are electron donating more “glue” Stronger e - withdrawing/donating character of groups attached to atom with basic lone pair Base: strength depends on: H N H H H 3 C N CH 3 C H 3 Section 12.5 Predicting Base Strengths More electronegative, more e - withdrawing less “glue” Weaker F N F F Predicting Base Strengths - Summary For F 1- , Cl 1- , Br 1- , and I 1- : the strongest base has the weakest conjugate acid I 1- < Br 1- < Cl 1- < F 1- Section 12.5 For Bases with Nitrogen: the strongest base has more e- donating groups NCl 3 < NH 3 < N(CH 3 ) 3 For Polyatomic ions with a differing number of oxygens: the strongest base has the lowest oxidation state (least oxygen) NO 3 1- < NO 2 1- For Polyatomic with a different central atom : the strongest base has the least electronegative central atom ClO 4 1- < BrO 4 1- < IO 4 1- Pick the strongest acid, and the strongest base below. 1. HI, I 1- 2. HI, Cl 1- 3. HCl, Cl 1- 4. HCl, I 1-
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Pick the strongest acid. 1. HIO 4 2. HIO 3. HBrO 4 4. HBrO Pick the strongest base. 1. HSO 4 1- 2. HSO 3 1- 3. HSeO 4 1- 4. HSeO 3 1- HA (aq) + H 2 O (l) A 1- (aq) + H 3 O 1+ (aq) K = [Products] [Reactants] [A 1- ][H 3 O 1+ ] [HA][H 2 O] K = The stronger the acid the more H 3 O 1+ is produced, the bigger the K a . K = [A 1- ][H 3 O 1+ ] [HA] base Acid Dissociation Constant a Section 12.6 & 7 K a acid strength measured relative to water Acid Dissociation Equation: H 2 SO 4 (aq) + H 2 O (l) HSO 4 1- (aq) + H 3 O 1+ (aq) K ~ [P] [R] HA,B - A - ,HB E Rxn Coordinate No such thing as H 2 SO 4 (aq) Only H 3 O 1+ (aq) >>1 Extensive A lot of product X Section 12.6 & 7
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/30/2010 for the course CH 101 taught by Professor Bigham during the Fall '08 term at N.C. State.

Page1 / 7

12.5-12.8 - Predicting Acid Strengths - Summary For H-F,...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online